Many types of printers use a cartridge that contains a printer ribbon saturated with ink. Typically, the printer ribbon is in the form of a continuous loop that is withdrawn from one arm of a cartridge and returned to the opposite arm of the cartridge by a drive mechanism, such that an exposed length of ribbon extends between the two arms of the cartridge between print hammers and a printing surface. As the ink contained in the ribbon is depleted, the print quality becomes lighter, and eventually is unacceptable. However, the ink contained in the ribbon is typically depleted before the ribbon wears out. Therefore, many ribbon cartridges contain a reinking system to continuously provide ink to the ribbon as the ribbon moves through the cartridge.
Conventional reinking systems typically consist of a circular, rotating sponge that is saturated with ink. The sponge is in frictional contact with a transfer roller, which in turn is in frictional contact with the ribbon. As the transfer roller rotates, it draws a film of ink from the sponge and deposits it on the ribbon. Typically, the width or height of the sponge and transfer roller are the same as the width of the ribbon, such that ink is provided uniformly across the width of the ribbon.
However, some printers, such as dot matrix line printers, use two rows or banks of hammers, which allow them to print two lines of data simultaneously. As the printer ribbon moves between the banks of hammers and the print medium, the ribbon is angled across the banks to utilize the majority of the ribbon width, while leaving a small edge margin that is not impacted by the hammers to protect the sensitive edges of the ribbon. As a result, three print zones are created on the ribbon. The center zone of the ribbon is impacted by both rows of hammers, and is referred to as a "double strike zone." Zones on either side of the double strike zone, adjacent opposing edges of the ribbon, are impacted by only one of the upper and lower banks of hammers. These two zones are therefore commonly referred to as a "single strike zone." As a result, twice as much ink is extracted from the double strike zone as from each of the single strike zones in a given period of time. The use of ink therefore varies across the width of the ribbon, although conventional reinking systems replenish ink to the ribbon in a uniform manner across the width of the ribbon.
Accordingly, there is a need in the art for an improved system for reinking a ribbon of a printer ribbon cartridge, and in particular, a reinking system that provides a selected, variable profile of ink across the width of a printer ribbon. The present invention fulfills these needs, and provides further related advantages.